1. Field of the Invention
The present invention relates to a data recording apparatus writing data on/reading data from a hard disk drive in response to a command received from an upper control device.
2. Description of the Related Art
Apparatuses with redundant array of inexpensive disks (RAID), or RAID apparatuses, are those in which a RAID technology is used to record AV data (i.e., video data and audio data) on a plurality of hard disk drives. Such RAID apparatuses have been widely used as data recording apparatuses for business and professional purposes. In general, such RAID apparatuses carry out write/read operations of AV data in response to commands transmitted from upper control devices.
Hard disk drives have restrictions on access time (i.e., time before actually carrying out a data-write/read operation after receiving a data-write/read command) due to seek time of a head or rotational delay of a target sector.
Therefore, a system continuously reproducing AV data without interruption has been designed to use a specific format to appropriately arrange AV data on hard disks in a RAID apparatus, thereby assuring a high data rate at the time of reading/writing operation (see, for example, Japanese Unexamined patent application Publication No. 2000-076021).